eMarketer On Social Networking In The US: 57% On Facebook, 11% On Twitter

Research firm eMarketerestimates that more than half of adult internet users in the US were logging on to Facebook at least once per month at the end of last year. In 2011, the company forecasts that 132.5 million US web users will use the site monthly. Twitter, it adds, will enjoy faster growth rates in the near future but continue to attract ‘relatively few’ online Americans.

An increase of 13.4 percent in the number of users would mean Facebook will reach almost 9 in 10 social network users and 57.1 percent of Internet users this year.

By 2013, eMarketer estimates 62 percent of Web users and almost half (47.6 percent) of the overall US population will be on Facebook.

Twitter, in contrast, was used by 16.4 million US adults, or 9% of the adult internet population, at the end of 2010. eMarketer expects growth to surpass 26 percent in 2011 as Twitter reaches 11% of Internet users and 16.5% of adult social network users in the United States. By 2013, eMarketers forecasts nearly 28 million Americans will be tweeting.

eMarketer’s estimates are based on analysis of survey data and visitor statistics from over a dozen sources, and include US users who use any Internet-enabled device to access their Facebook and/or Twitter accounts at least once a month, including access through third-party apps.